The field of advanced digital signal processing methods is one of the fastest developing scientific and technical disciplines, and is important in the field of Shunt Active Power Filter control methods. Shunt active power filters are highly desirable to minimize losses due to the increase in the number of nonlinear loads (deformed power). Currently, there is rapid development in new adaptive, non-adaptive, and especially hybrid methods of digital signal processing. Nowadays, modern methods of digital signal processing maintain a key role in research and industrial applications. Many of the best practices that have been used to control shunt active power in industrial practice for decades are now being surpassed in favor of new progressive approaches. This systematic research review classifies the importance of using advanced signal processing methods in the field of shunt active power filter control methods and summarizes the extant harmonic extraction methods, from the conventional approach to new progressive methods using genetic algorithms, artificial intelligence, and machine learning. Synchronization techniques are described and compared as well.

A novel diagnosis method based on the rotor slip is proposed in the paper to correctly detect current and speed sensor failures during the induction motor drive (IMD) operation. In order to enhance reliability and avoid confusion in the diagnosis algorithm due to the influence of measured signal quality, each fault type is determined in a priority order defined by the diagnosis method. Based on the features of the IMD applying the field-oriented control (FOC) technique, an innovative model uses the measured currents and reference speed as the input signals to estimate the rotor slip for the current sensor fault detection. After verifying the quality of the feedback of the current signals, a speed sensor fault function is continued, and performs according to relations among the reference speed, estimated speed based on the sliding mode method, and measured rotor speeds. Finally, the estimated quantities are selected to replace the wrong measured current or speed signals. The feasibility of the proposed approach is verified by simulations using Matlab-Simulink software as well as by practical experiments using an IMD prototype with a rated power of 2.2 kW and a DSC-TMS320F28335-based control system. The obtained simulation and experimental results demonstrated the feasibility, effectiveness, and reliability of the proposed diagnosis technique in detecting sensor failures and maintaining the stable operation of the IMD.

This paper proposes a fault-tolerant control (FTC) strategy using the current space vectors to diagnose sensor failures and enhance the sustained operation of a field-oriented (FO) controlled induction motor drive (IMD). Three space vectors are established for the sensor fault diagnosis technique, including one converted from the measured currents and the other two calculated from the current estimation technique, respectively, measured and with reference speeds. A mixed mathematical model using three space vectors and their components is proposed to accurately determine the fault condition of each sensor in the motor drive. After determining the operating status of each sensor, if the sensor signal is in good condition, the feedback signal to the controller will be the measured signal; otherwise, the estimated signal will be used instead of the failed signal. Failure states of the various sensors were simulated to check the effectiveness of the proposed technique in the Matlab/Simulink environment. The simulation results are positive: the IMD system applying the proposed FTC technique accurately detected the failed sensor and maintained stability during the operation.

In this study, we present the results of measuring the performance of selected Peltier cells such as thermoelectric Peltier cooler modules (TEC), thermoelectric micro-Peltier cooler modules (TES), and thermoelectric Seebeck generator modules (TEG). The achieved results are presented in the form of graphs of powering system output voltage or power efficiency functions of the load impedance. Moreover, a technical solution is also presented that consists of designing a water consumption power supply system, using a renewable energy source in the form of a Peltier cell. The developed measuring system does not require additional batteries or an external power source. The energy needed to power the system was obtained from the temperature difference between two sides of a thermoelectric cell, caused by the measured medium which was flowing in a copper water pipe. All achieved results were investigated for the temperature difference from 1 to 10 K in relation to the ambient temperature.

This study focused on the design of the power supply and the overall control structure of the electronic system, which is charged only with energy from the environment. It describes the basic finding of all the necessary information for the design and implementation with the measurement and evaluation of characteristic parameters. The paper describes the individual possibilities of obtaining energy from the surroundings with the selected energy from the heat of the pipeline. There are also various arrangements of possible elements mentioned in order to ensure the optimal solution of the whole system. Furthermore, a basic evaluation of the comparison of a possible workable solution is made.

This paper presents an improved sensorless scalar control (SC) scheme for in-duction motor drives, aimed at enhancing speed tracking capability in the low-speed region. The proposed method integrates rotor flux-based model reference adaptive system (RF-MRAS) with dual adaptation to estimate both rotor speed and stator resistance. The rotor flux angle obtained from the current model (CM) is used to compute the synchronous speed, while the slip component is filtered before being injected into the scalar frequency com-mand. In addition, a stator-voltage-drop compensation strategy based on estimated stator resistance is introduced to preserve the air-gap flux during low-voltage operation. Simula-tion studies confirm that the proposed method extends the stable operating range. The min-imum stable speeds are 12.23/12.28 rad/s at 20% load, 10.78/11.59 rad/s at 25% load, and 11.88/11.29 rad/s at 30% load, evaluated using EMAPE/Emax criteria. All cases satisfy EMAPE ≤ 2% and Emax ≤ 6%, showing better low-speed stability than the baseline methods. Laboratory experiments were also performed on an induction motor drive platform. At 300 rpm, online stator resistance estimation strongly reduces speed oscillations under a 20% stator resistance increase. At very low speeds, voltage compensation restores the ef-fective stator voltage and improves steady-state tracking. These results verify that the pro-posed dual RF-MRAS scheme improves robustness without requiring mechanical speed sensors.